Hydraulic lock



mmh 2n, i195@ A R, PATRICK 50u39 HYDRAULIC LOCK l Filed Oct. 26, 1945 Patented Mar. 21, 1950 UNITED STATES PATENT oFFICE HYDRAULIC LOCK Audie Ross Patrick, Kansas City, Mo.

Application October 26, 1945, Serial No. 624,859

1 Claim. l

This invention relates to hydraulic locks of the character adapted for positioning in the ow line of an hydraulic system, and the primary aim is to provide simple, eiective and positively acting means for preventing the back flow of fluid in the system and to lock liuid in that portion of the system to one side of the means, which has structure for releasing the lock to permit movement of the liuid in the system in either direction.

A further aim of the invention is to provide a lock of the aforementioned character, wherein the releasing structure is manually operable and capable of shifting to and from an effective position without danger of causing the component elements of the lock to become maladjusted.

Structural features of the hydraulic lock are important and other objects of the invention pertaining thereto will appear during the course of the following specification, referring to the accompanying drawing, wherein:

Fig. 1 is a side elevational view of an hydraulic lock made in accordance with the present invention and associated with the hydraulic braking system of an automobile.

Fig. 2 is a longitudinal central sectional view through the lock.

Fig. 3 is a transverse cross sectional view taken on line llI-l'll of Fig. 2; and

Fig. 4 is another cross sectional View taken on line IV-IV of Fig. 2.

The lock is positioned in the ilow line of an hydraulic system and in the instance illustrated, the automobile has a master cylinder Ill from which conduit I2 receives fluid under pressure when 'the brake pedal of the automobile is depressed.

When the hydraulic lock, as contemplated by this invention is installed, it receives fluid from conduit I2 and as the iluid passes through conduit I4 to the work, a valve member i6 within body I8 is forced from its position on seat 2D where it is normally held by the influence of spring 22.

Seat 2li is made of resilient material and held in operative position by snap ring 24 engaged within an annular groove of body IB. A passage 26 extends through body I8 from one end thereof to the other, and this passage is contoured as clearly illustrated in Fig` 2, to allow for the introduction of plug 28 that is in screw-threaded engagement with body I8 at one end thereof. It is this plug 28 that holds spring 22 in position against one end of valve member IIS.

Plug 28 has an opening 3B in communication with conduit I4 and when valve member IE is lifted from its seat, fluid under pressure is free to flow through passage 26 from inlet port 32 to the outlet port, which is formed by opening 30. Valve member lt is designed to allow expansion and contraction of the fluid locked within that portion of the system to one side of the body and which includes conduit I4. If, for example, the oil or other fluid is locked in the Isystem or in conduit I 4 and friction or other action increases the temperature, the fluid may expand into chamber 34 provided in valve I6 but held normally closed by ball 3S which closes bore 38.

A spring 4l] yieldably maintains ball 3G in a place where bore 3B is closed, and since chamber 34 is in connection with passage 26 through nleeder opening 42, any fluid that may force its way into chamber 34 will enter that portion of passage 2G and thence the part of the system wherein fluid under pressure is not locked under pressure. In other words, there is always a lower pressure in that part of passage 26 adjacent to bleeder opening 42 when valve member I6 is` functioning than the pressure in conduit I4 and the adjacent part of passage 26.

To maintain the lock in a position where the fluid may iiow to and fro as it is put to work, valve member I6 is held out of its position upon seat 2D. The movement of this valve I5 into a place where the fluid may ilow with equal ease in either direction, must be accomplished without injury to the parts of the lock and without danger of binding the same. Accordingly, control shaft 44 is rotatably mounted in body I8 by plug 46 that is in screw-threaded engagement with a sleeve 48 threadingly rmounted within passage 26 of body I8. This sleeve 48 is directed inwardly, as illustrated in Fig. 2, and has a cam face 5i! developed on the inner end thereof, Plug 46 journals shaft 44 and leakage therearound is prevented by packing 52 held in place by ring 54. A set screw on the shaft 44 overlies the plug 46 for limiting downward movement of the shaft 44 into sleeve 48.

A socket 56 formed in shaft 44 is polygonal in cross section and receives a neck 58 on anvil 6I). This anvil has a cross pin 62 therethrough to bear upon cam face 5l). The pressure of fluid in the system maintains pin 62 against cam face 5i) and as shaft 44 is turned about its axis, anvil 6l? moves longitudinally toward and from the adjacent end of valve member It. When the innermost portion of cam face 5l] is against pin 62, valve I6 is moved from its place on seat 20 and no locking of the uid in one portion of the system to one side of body I8 occurs.

Shaft 44 has an arm 64 adjustably mounted therein by set screw 66 and an actuating rod 68 attached to arm 64 by coupling l() extends to a knob 12 on the instrument board 14 of the automobile. Thus, when the hydraulic lock is used in connection with the braking system of an automobile and it is desired to set the brakes, the brake pedal is depressed with the parts of the lock in the condition shown in Fig. 2. Fluid in conduit i4 and the conventional tubes joining that said conduit with the brake structure of the automobile wheels, will be maintained under full pressure and the brakes will be secured against release.

Vifhen it is desired to return the braking system to a condition ol normal operation, actuating rod 68 is pulled to turn shaft i4 and move anvil Gil down against valve I6 to unseat the same, and therefore, establish an unrestricted passage 2S through body I8 from intake port 32 to outlet port 3l). In such condition, the brakes are applied and released by movement of the brake pedal.

The utility of the hydraulic lock has been made clear by describing the same as usable with an automobile braking system, but it will be clear to those skilled in the art that the lock may be employed elsewhere with equal effectiveness.

Having thus described the invention, what is claimed as new and desired to be secured by :30

Letters Patent is:

In a lock of the kind having a hollow body provided with an inlet port and an outlet port and adapted to be interposed within the flow line of an hydraulic system, said body having a valve member therewithin reciprocable to and from a position for blocking the passage of fluid through the body, said valve member being provided with means for yieldably holding the same biased in said position, improvement cf which comprises actuating means for the valve member including a cam face formed within the body; a shaft journaled for rotation in the body in alignment with the valve member; and an anvil floatingly mounted in the body between said shaft and said valve member, said anvil being operably connected with the shaft for rotation thereby and being freely movable toward and away from the shaft on the rotative axis of the latter and having a radially extending cross pin bearing against said cam face, whereby as the shaft is rotated, reciprocable movement is imparted to the anvil and to said valve member.

AUDIE ROSS PiTRICK.

REFERENCES CITED The following references are ol record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,374,860 Miller Apr. 12, 1921 1,627,486 Cravens May 3, i927 2,310,485 WyckoilC Feb. 9, 1943 2,336,700 Pepersack Dec. 14, 1943 

